Binding machine



Feb. 21, 1961 A. LECOCQ 2,972,294

BINDING MACHINE Filed Aug. 5, 1957 5 Sheets-Sheet 1 Fig.7

A. LECOCQ BINDING MACHINE Feb. 21, 1961 5 Sheets-Sheet 2 Filed Aug. 5, 1957 Fig. 1/

Feb. 21, 1961 AQLECOCQ BINDING MACHINE Filed Aug. 5, 1957 5 Sheets-Sheet 3 A. LECOCQ BINDING MACHINE Feb. 21, 1961 Filed Aug. 5. 1957 5 Sheets-Sheet 4 F IG 6 FIG. 5

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Feb. 21, 1961 A. LECOCQ BINDING MACHINE 5 Sheets-Sheet 5 Filed Aug. 5, 1957 3 T m 9w ll 5 WW R wk MD (M 3w H .nit

BINDING MACHINE Filed Aug. 5, 1957, er. No. 684,383

Claims. (Cl. 100- 10) This invention relates to binding machines, especially (though not exclusively) suitable for use in rolling mills for binding coils of strip steel and the like. In order to permit continuous operation of the mills, thecoils have to be bound immediately as they issue from the mill Without it being possible to allow them I to cool, since they have to be handled continuously for delivery to further processing stations or to storage if the rolling mills are to operate with full efliciency without shutdown due to bottlenecks in the discharge of the rolled stock.

Binding operations of the kind just specified have here tofore generally bene performed manually, and due to ts arent O the high temperature of the rolled stock to be bound the operators had to wear insulating overalls. Even so, working conditions are extremely severe and an operator is hardly able to effect more than about ten binding operations per working shift; operators at the binding station usually have to be changed in quick rotation, because of the heat to which they are exposed.

It is an object of this invention to provide a binding machine capable of performing work of the character just described, and one that can be controlled or supervised by a human operator stationed at a comfortable distance from the hot stock being bound. It is, therefore, an object of the invention greatly to improve sanitary conditions and working efficiency in the operations specified. 1

A binding machine according to the invention may essentially comprise a gripper means mounted for move ment preferably in a vertical direction, said means being in the form of a pincers or tongs having two interpivoted legs, guide means at the ends of said legs for guiding a binding element such as a length of wire or steel strip, a welding electrode positioned adjacent the end of one of said legs, means for moving the legs towards and away from each other, and means for bodily moving the gripper means in said preferably vertical direction.

In the operation of a machine according to the invention, the coil or pack to be bound is delivered to a position below the gripper in substantial vertical alignment with it, after first having inserted a binding element into the guide means, such as a metal strip somewhat exceeding in length that of the periphery of the coil or bundle to be bound. The gripper is then moved downwards and its legs are simultaneously moved apart to encompass the bundle. In this movement the binding element supported in the guide means is applied against the upper end face of the bundle and thereafter against the lateral surfaces thereof on continued descent of the gripper. After the gripper has'been moved down a sufficient distance so that the ends of both legs of it have passed beyond the bottom of the bundle, the gripper legs are moved inwards, thereby causing the binding element to be applied against the horizontal under surface of the bundle. The electrode is thereupon moved to operative position and the adjacent ends of the binding element are welded together.

The gripper legs are then moved apart, the gripper is bodily moved upwards and the bound coil or bundle can then be removed and a fresh bundle inserted in its stead, or if desired, the same bundle may be turned over to a dilferent position and a further binding element applied around it.

1 Preferably, the welding electrode is movably mounted upon the gripper leg which supports it, and its-position thereon may be controlled as by means of a pressurefluid actuator.

In a simple form of embodiment the gripper legs may simply be urged towards each other by a spring. However, in order to ensure a more reliable and positive engagement of the binding element about the surface of the coil, a fluid pressure actuator is preferably provided to assist, or replace, the spring action. This fluid actuator may be of the single-acting type, or it may be of the double-acting type whereby it will also serve in assisting the opening movement of the gripper after-the binding element has been positioned.

In one desirable embodiment of the invention, the gripper legs when in their open condition, are spaced apart an amount greater than the greatest thickness dimension of the coil substantially throughout the full length ofsaid legs, and one of these latter is formed with ahead at its end which supports thewelding electrode and-is adapted to engage the extremity of the other leg. This other leg is preferably provided with a fluidactuated pusher element for bending back the welded ends of the binding element towards the electrode.

According to a feature of the invention, adjustable means may be associated with the gripper for automatically regulating the feed of the binding element.

In a preferred form of the invention, the components of the improved binder apparatus are operated with compressed air actuators, and the flow of air is controlledin the proper sequence by means of electro-valves controlled through an electric timer circuit having contact means adapted to be automatically closed and opened in the desired sequence by the action of the components of the machine to provide for the desired cyclic operation.

The objects, features and advantages of the invention will be made clear from the ensuing description given by way of example but not of limitation with reference'to the accompanying drawings wherein a preferred embodiment of the improved binding apparatus is illustrated. Fig. l is a general view of the machine in elevation; Fig. 2 shows a circuit controlling the positioning of the feeder mechanism of the machine; i

Fig. 3 is a large-scale view showing the construction of the gripper assembly;

Figs. 4-to 9 are smaller-scale diagrammatic views of the gripper assembly in various operating positions; Fig. 10 is a circuit diagram of the timer circuit con trolling the general operation of the machine; and I Fig. 11 illustrates the pressure fluid control system. Referring to the drawings, Fig. 1 illustrates a general view of an improved binding station in side elevation. Shown adjacent to the binding machine is a proper conveyor belt or the like, designated by reference 1, for feeding to the binding machine a succession of bundles to be bound, one of which is shown at 3. The bundle 3 is shown by way of example as comprising a hollow-core coil of metal strip, and is viewed in the figure in axial section. Each coil as it reaches the station is placed on the top of an air-actuated hoist table 5 which is then operated to raise the coil to a binding position. On completion of the binding operation the hoist table lowers the bound coil back on to. the conveyor 1. It will be understood that ancillary equipment such as the conveyer belt and hoist table just mentioned form no part of the present invention and may be constructed in any suitable, conventional manner.

The binder machine of this invention is shown as comprising an upright standard 9, projecting from a suitable base, not shown. Secured to a side of the standard is a rack member 11 of appreciable extent. An upper frame or sup-port 13 has one end recessed to be slidable about the standard 9 and projects horizontally from the standard in cantilever relation therewith. A gear (not shown) journalled in the upper frame 13 meshes with the rack 11 and is manually rotatable by means of crank handle 25 for adjusting the vertical position of the frame 13 on the standard 9. The frame can be locked in adjusted position by means of a latch 27. Supported from the opposite end of frame 13 is a vertical compressed-air cylinder 15 in which a piston 17 is slidable. Piston rod 19 projects upwardly from piston 17 and extends through the upper cylinder head and has its upper end connected by way of a horizontal cross-bar 19 with the top of a generally vertical gripper assembly generally designated 21. A stop bushing 23 supported at the end of a horizontal arm projecting from the top of standard 9, serves to limit the downward movement of the gripper assembly 21 by abutment against the under face of cross-bar 19. As later described, an air damper preferably cooperates with the stop 23 for cushioning the shock at the end of such downward movement.

Also supported around the standard 9 to project horizontally from the standard in cantilever relation therewith, below the upper frame 13 is a lower frame 29 which generally supports the mechanism for feeding, shearing and metering the bonding element to the machine. In a manner similar to upper frame 13, lower frame 29 is adjustable in vertical position upon standard 9 by means of a crank handle 31 which serves to rotate a pinion (not shown) meshing with rack 11; a latch 33 serves to lock lower frame 29 in adjusted position.

A table extension of lower frame 29 towards the right of it as shown in Fig. 1 serves to support a rotatable reel 35 comprising a store of binding element, such as wire or steel tape 37. The tape 37 as it is fed from the reel is passed through a conventional straightener device 39 comprising three idler rollers.

The main portion of table 29 serves to support the binding element driving and shearing mechanism. The driving mechanism comprises a pair of drive rollers 43 journalled on opposite ends of a pivoted lever 45 and driven continually in rotation through appropriate gearing, not shown, from a suitable drive shaft. A pair of backing rollers 53 are idly journalled on stationary pivots of the frame adjacent the respective drive rollers 43. The lever 45 is normally positioned at an angle such that the drive rollers 43 are spaced from the idler rollers 53 so that the bond element 37 may be passed freely between each pair of drive and backing rollers 4353 without being driven thereby. However, on energization of a solenoid R an armature is displaced and, through suitable linkage as schematically indicated in the drawing, the lever 45 is rocked to the operative position shown wherein each drive roller 43 presses the bond element 37 against the adjacent backing roller 53, whereupon the bond 37 is frictionally driven leftward according to Fig. 1.

The bond shearing mechanism comprises a shear assembly 55 including a stationary shear element and a cooperating rockable shear element actuated through linkage by a pneumatic actuator 57. The bond element 37 issuing from the feed mechanism is passed between the shear elements so as to be severed there at each time actuator 57 is operated to rock the movable shear element.

The feeding and shearing mechanisms just described are mounted on a common carriage so as to be bodily displaceable longitudinally on the lower frame 29. For effecting such displacement the frame 2? has a rack 63 secured thereto longitudinally of it, and a gear 61 in mesh with the rack is secured on the shaft of a reversible D.-C. motor 59 mounted on the mechanism carriage. Thus when the motor 59 is energized the feeding and shearing mechanisms may be displaced bodily along the frame 29 for adjusting purposes. Displacement of the carriage along the support is effective, through gearing 67, to rotate a potentiometer arm 64 along a potentiorneter resistance as so as to generate a voltage signal corresponding to the position of the mechanism carriage relative to frame 29, as will be presently described in greater detail.

Also mounted on lower frame 29 in displaceable relation with it, adjacent the free end of said frame (to the left of Fig. l) is a length-metering mechanism for determining the length to which the bond element 37 will be sheared, and comprising a vane 71. The metering mechanism is mounted upon a carriage which is shiftable along the lower frame 29 by means of a reversible D.-C. motor 73 mounted on the carriage and driving a pinion 75 which meshes with a rack 77 secured to the frame 29. A potentiometer arm 78 is displaced over a potentiometer resistance 79 through gearing 81 to generate a voltage signal corresponding to the position of the metering device 71 on the frame.

By the means just described, the feeding and shearing mechanism, and the metering mechanism, can be adjustably positioned independently of one another along the lower frame 29 to take care of different lengths and sizes of bundles or coils 3 to be bound. Various diameters of the coils are handled by vertical adjustment of the lower frame 29 along the standard 9 as previously described.

Referring to Fig. 2, a potentiometer positioning circuit will now be described for controlling the position of the driving and shearing mechanism along the lower frame 29. It will be understood that a similar control circuit is used for controlling the position of the metering mechanism.

Across the supply lines 83 and 84 indicated as carrying respectively a positive potential V+ and a negative potential V-, there is connected a potentiometer resistance 85 along which an arm $6 is manually adjustable for selecting a desired position of the shears 55 on the frame 29. A scale calibrated in distance cooperates with arm 86. Also connected across the lines 83, 8 4 to provide a Wheatstone bridge circuit with potentiometer resistance 85 is a potentiometer resistance 65 described in connection with Fig. l as having its arm 64 rotated through gearing on displacement of the shear mechanism. Connected across the free diagonal of the bridge circuit, i.e. between potentiometer arms 86 and 64, is a polarized relay winding 87 acting to close one or other of its opposite relay contacts 87a, 87b depending on the polarity of the current flowing through relay winding 87. in other words contacts 87a or contacts 87b are closed depending on the sense of error between the desired and actual position of the feed and shear mechanism on the frame. When the desired position is attained both contacts are open. Closure of contacts 87a energizes a power relay 88 and closure of 87b energizes a power relay 89. Depending on the power relay energized, contacts 88a or 89a are closed, completing an energizing circuit between lines 83-84 for one or the other of the field windings 59a, 59b of D.-C. motor 59, whereby the motor is rotated in the proper sense to displace the mechanismsupporting carriage to the desired position on lower frame 29. When the desired position is reached motor 59 is deenergized. It will be understood that any desired type of positioning servo-system may be utilized instead of that just described in connection with Fig. 2.

Turning to Fig. 3, the construction of gripper assembly 21 is shown in detail. The assembly comprises a pair of parallel spaced legs 91 and 93, leg 93 being rotatable about a pivot 95. A spring 97 biases leg 93 towards leg 91. A pneumatic actuator has its cylinder 101 pivoted to leg 91 and its piston 99 pivoted to leg 93. A lower section 103 of leg 93 is electrically insulated from the upper section of the leg by way of an insulator joint 105, and said lower section is formed as a camming or follower head including an incline or ramp surface 107. A pair of rollers 109 are journalled on the end of the head. Movably mounted on the head 103 is a welding electrode 111 provided with a steel spur 113 at its end. The electrode 111 has one end secured to a piston 115 slidable in a cylinder 117 securely carried by the head 103, and the projecting end of the cylinder 117 at 118 is connected with a source of voltage. A biassing spring 112 is positioned in the cylinder to bias the electrode 111 to a retracted position. A cooperating welding electrode 119 is fixedly mounted by way of an insulated support on the leg 91 of the gripper. Extending through a hole in electrode 119 is a finger or push-rod 121 attached at its outer end to a piston 123 operating within a compressed air cylinder 125 for a purpose to appear later. A spring in the cylinder biasses the push-rod 121 towards its retracted position.

Formed in the legs 91 and 93 near the lower ends thereof, in normally aligned relationship, are guide passages 127 which are formed with rounded flared entrances as shown, and serve to guide the binding element in a manner to appear later. A presser foot 129 is carried at the lower end of a rod 131 which is slidable in a vertical guide 133 having its upper end secured to a cross bar of the gripper assembly 21, and a spring 134 in the guide biasses the presser foot to its extended position. Thepresser foot, as will be described in detail hereafter, serves to hold down the binding element in position during a binding operation.

As already indicated, the preferred embodiment of the binding machine herein described is operated by compressed air; while the use of compressed air simplifies the supply piping in that return connections need not be provided since the exhaust air may be dumped to atmosphere, it will be obvious that an hydraulic power fluid may be used in place of air with only minor modifications in the equipment shown and described herein.

The general operation of the machine as so far described proceeds as follows. Prior to a binding operation, a bundle to be bound, such as a coil of strip steel 3, is positioned on the hoist table 5 as shown in Fig. 1 and the gripper assembly 21 is in its uppermost position. Solenoid R0 is energized, rocking arm 45 to initiate the feed advance of the binding element 37 as previously described. The band 37 is fed from the store 35 and advanced through rectifier rollers 39, driven rollers 43 53, shears 55 in idle, i.e. open, position, and through the aligned guide apertures 127 in the gripper legs, it being noted that at this stage the gripper assembly is in its uppermost position, with piston 17 at the top of cylinder 15 (as already mentioned), so that the apertures 127 are in alignment with the shears 55. Upon the top of the binding element engaging the vane 71, the vane is rocked, sufficiently to open contacts (later described) whereby the energizing circuit for solenoid R0 is opened. The rocking lever 45 is therefore now rocked to its idle position and the drive rollers disengage the binding element so that its advance is arrested. At the same time, shears 55 are operated by actuation of the piston 57, so that the element is cut off to a predetermined length as determined by the preadjusted relative positions of the feedand-shear mechanism and of the metering mechanism or vane 71 on the lower frame 29.

At this point, the relative positions of the gripper assembly 21, binding element 37 and bundle 3 are as shown in Fig. 4. Compressed air is now delivered into the top of cylinder 15, so that the gripper assembly starts to move downward. In this movement an intermediate portion of the binding element 37 is deposited across the upper face of coil 3 and is blocked thereon by presser 129.

As the gripper proceeds on its downward stroke, follower head 103 is carnmed outwards owing to the ramp 107 riding over an edge of the coil 3, while the binding element 37 engages the inner vertical side of the coil 3 on one side, and engages the ramp 107 on the other side. The resulting condition of the system is shown in Fig. 5.

Shortly before the gripper 21 has reached the lowermost end of its stroke, compressed air is applied to the right side of piston 99, which thereby assists the action of spring 97 in moving the gripper leg 93 to its closed position (see Fig. 6). Thus, as the gripper reaches its lowermost position and the follower head 103 moves past the lower end of the coil 3, the combined action of spring 97 and actuator piston 99 serve to return the gripper leg 93 to its closed position as shown in Fig. 7. As a result, it will be seen that camming head 103 acts to carry with it a part of the binding element so as to bring it along side the other part. The coil is at this stage encircled with a length of binding element 37. Piston 115 is now actuated by application of compressed air and electrode 111 is thereby advanced so that the spur 113 acts to apply the adjacent ends of the element 37 firmly against each other as in Fig. 8. As the electrode engages the ends of the element 37 current flows thereacross to the cooperating electrode 1 and the two ends of the bond are welded together. After a predetermined time the electrode is restored to idle position. Compressed air is then applied to the left side of piston 99 to move the legs 91 and 93 apart. During this time the piston 123 was actuated so as to move pushrod 121 outwards of cylinder 125, thereby bending back the welded tips of the element 37 (Fig. 9). The piston 17 is now actuated by compressed air delivered to the lower end of cylinder 15, so that the gripper assembly is moved upward back to its initial position. Hoist table 5 is lowered, the bound coil 3 is taken up by the conveyor belt 1 and a fresh operating cycle may set in.

Means will now be described with reference to Figs. 10 and 11 for accomplishing the above timed sequence of operations automatically. Figs. 10 and 11 are circuit schematics of the electric and pneumatic parts of the system respectively.

Referring first to Fig. 10, the supply lines 83 and 84 are supplied with voltage V+ and V from a power supply by way of acircuit breaker CD. A signal lamp L1 serves to indicate to the operator that the system is under power. Across the lines 83-84 a number of circuits are conneoted, which are generally designated, for convenience of description, by the Roman numerals from I to VIII.

For convenient reference, the various circuit elements appearing in Fig. 10 will first be listed in succession; their functions however will become more apparent in the subsequent description of a complete operating cycle of the machine:

ad is a pair of contacts serving to arrest the feed of the bonding element.

Phl is a pair of contacts closed when gripper 21 is in its uppermost position.

P1, P2, P3 are contacts actuated by metering vane 71.

C1, C2 are switch contacts respectively closed and open when the shears have acted to sever the bonding element.

D is a manual start switch, and D is a switch mechanically linked thereto.

D1 is a switch closed when the gripper is restored to closed position by air piston 99.

FCa and FCb are contacts actuated by gripper 21 on approaching the lowermost end of its travel, e.g. 2 inches short of the lowermost point.

FCc is contact actuated by gripper 21 on approaching, e.g. 2 inches short of, the uppermost point of its travel.

FM1 and FM2 are contacts closed in the closed condition of the gripper legs 91, 93.

L2 is a signal lamp indicating that the binding element is in place.

MM are contacts closed when the legs of the gripper reach a position half-way to the fully spread-out position t rs f- GM! and M2 are contacts closed on the gripper legs reaching their fully spread-out position.

h are contacts which are actuated by piston 123 and, piston 123 also serves to actuate rod 121 to bend down or fold the welded or soldered ends of hte element 37.

CV is an emergency switch for arresting the welding operation.

DP is a time delay relay.

DP2, DPS, DP4, DPS, DP7 and DPS are contacts delayedly actuated by time relay DP.

R0 is the previously mentioned solenoid winding controlling the feed of binding element 37.

R1 is a relay winding controlling an electro-valve EV1 for operating pneumatic piston 57 actuating shears 55.

R2 is a relay winding controlling an electro-valve EVZ for operating pneumatic piston 17 for downward movement of gripper 21.

R3 is a relay winding controlling an electro-v-alve EV3 for operating pneumatic piston 99 for inward movement of the legs of gripper 21.

R4 is a relay winding controlling an electro-valve EV4 for operating pneumatic piston 115 to advance welding electrode 111.

R5 is a relay winding controlling an electro-valve EVS for operating pneumatic piston 99 for outward movement of the legs of gripper 21.

R6 is a relay winding controlling an electro-valve EV6 for operating pneumatic piston 17 for upward movement of gripper 21.

R7 is a relay winding controlling an electro-valve EV7 for operating an air-damper associated with piston 17 for cushioning the arrival of the gripper assembly at the upper end of its vertical stroke.

R8 is a relay winding controlling an electro-valve EV8 for operating pneumatic piston 123 to fold down the welded ends of binding element 37.

r2, r3, 15 and r6 are holding and other relay windings associated in parallel with relays R2,R3, R5 and R6 respectively.

The contacts operated with the above listed relays are designated by the same symbols as the corresponding relay followed by a lower-case letter.

An operating cycle will now be described. It is assumed that the power lines 33 and 84 are under power as indicated by illumination of signal light L1. Since gripper assembly 21 is initially in. its uppermost position, relay winding R0 is energized from V-{- through closed contacts ad, C2, P3 and Pill, and winding R0 to V. Drive rollers 43-53 then operate to feed the binding element as already described until said element has rocked vane 71. When this occurs contacts P3 are opened and contacts P1 and P2 are closed. Closure of P1 prepares an energizing circuit for relay winding R1 and closure of P2 completes an energization circuit for signal lamp L2 which indicates to the operator that binding element 37 has been properly positioned in the guide apertures 127 of the gripper in uppermost position.

The operator then briefly depresses stant button D (circuit I). This energizes winding R1 by way of a circuit path from V+ through closed contacts D and'Pl and winding R1 to V-. Energization of relay winding R1 actuates electro-valve EV1 to actuate shears 55 to sever the element 37. Actuation of the shears causes contacts C1 0 close and C2 to open. Depression of start button D has simultaneously opened the ganged switch D to permit downward movement of the gripper assembly as will presently appear. In the present condition, relay winding R2 (circuit II) is energized from V-lthrough closed contacts P2 and C1 and Winding R2 to V; this actuates electro-valve EVZ to initiate downward movement of gripper 21. Winding r2 is energized simultaneously with R2 resulting in closure of contacts r262, establishing a holding circuit for relay winding R2; thus, as contacts P1, P2 and P3 actuated by vane 71 are restored to their initial positions on initiation of downward movement of the gripper,

relay windingRZ continues in energized condition. Upon follower head 103 reaching a point two inches or so short of its lowermost position, relay winding R3 (circuit Ill) is energized from V-]- through closed contacts FCa, lit: and winding R3 to V-. Energization of R3 actuates electro-valve EV3 to actuate piston 99 for supplying an additional force assisting biassing spring 97 in urging the gripper legs to closed position, Relay winding r3 is simultaneously energized to close contacts r3a and prepare the next circuit (circuit IV) for operation. As soon as the gripper legs have moved beyond the lower end of the bundle 3, leg 3 is moved inward under the combined action of spring 97 and piston 99, bending back the binding element 37 under the coil. When this closing movement is completed, contacts FM1 close and relay winding R4 is energized from V+ through closed contacts FCb, FMl, DPZ, D1, 1-3.1, winding R4, and closed emergency switch CV to V. Movable welding electrode 111 is now actuated by way of electro-valve EV4 and the ends of element 37 are welded together. Time relay DP connected in parallel with R4 is energized simultaneously with R4 and after a predetermined delay of say one half second, sufficient to ensure completion of the weld, all the six pairs of contacts associated with the time relay change condition. Specifically contacts DP2 are opened, deenergizing relay R4 so that electrode 111 is then re stored to idle retracted position by spring 112. Contacts DPS are opened (circuit ll), deenergizing holding relay r2 and relay R2, so that the downward pressure exerted on piston 17 to maintain gripper in its lowermost position is relieved. Contacts DPS are closed, whereby relay DP will be held in energized condition despite the opening of contacts PM Contacts DP iare closed, resulting in the energization of relay winding R5 (circuit V), causing electro-valve EVS to actuate piston 99 in a direction to move the movable gripper leg outward. it is noted that this outward movement is possible because of the simultaneous opening of contacts rSa in circuit III, whereby relay R3 is deenergized so that electro-valve EV3 is inactivated.

The closure of contacts DP7 prepares the completion of circuit VI. Meanwhile, as the legs of the gripper 21 reach a half-way open position, relay winding R8 (in circuit VIII) is energized from V+, through contacts DPS, MM and winding R8 to V. Energization of R8 operates electro-valve EVS to actuate push-rod 121 to bend down the welded extremities of element 37. Upon the legs of the gripper reaching their fully spread-out position, contacts 0M1 are closed, energizing relay winding R6. This activates electro-valve EVe to apply air pressure to the under face of piston 17, forcing the gripper 21 upwards. In the initial stage of this upward movement contacts FCa and PC!) are opened to prepare circuits III- and IV for a subsequent operating cycle. On the gripper 21 having reached its uppermost position contacts PCs are closed, so that relay winding R7 is energized from V through contacts FCC, FMZ, rfia and the winding R7 to V. Energization of relay R7 activates the air-damper to cushion the arrival of the gripper assembly at the upward limit of its travel.

Ganged manual switches S1 and S2 are provided for energizing relays R5 and R6 even though the gripper assembly is in its lowermost position, when desired to initiate an operating cycle from this condition of the machine.

Referring particularly to the compressed air supply circuit shown in Fig. 11, a pressure supply line is shown at AC as supplying the respective electro-valve mentioned in the above description. While the general operation of the system shown in Fig. 11 should be clear from the foregoing description, this figure illustrates the previously mentioned damper means in greater detail. Thus, a pair of air dampers are shown at A1 and A2, and serve to cushion the impacts at the upper and lower ends, respectively, of the vertical stroke of the gripper assembly.

In operation, it will be understood that the cut-off valve a2 is closed towards the end of the down-stroke of piston 17, thereby forcing the air exhausted from the lower end of cylinder 15 by piston 17 during the remainder of its downstroke, into damper cylinder A2, in which a springbiassed piston serves to develop the desired dampening effect. A similar action is accomplished by damper A1 at the upstroke of piston 17.

It will be understood that various modifications may be made in the illustrated embodiment without exceeding the scope of the invention.

What I claim is:

"1. In a binding machine, an assembly comprising a pair of spaced interpivoted legs, there being aperture means near adjacent ends of the legs for receiving a flexible binding element, means for bodily displacing the assembly toward an article to be bound so that the legs encompass the article with the portion of said element between the legs partly encircling the article, a projecting part mounted on the free extremity of one of said legs, biassing means for normally urging said projecting part toward the other leg, and a cam member on said projecting part, engageable by said element and pivoting said one leg away from the other leg by coaction with a surface of said article, said biassing means causing said projecting part to return to its normal position on continued displacement of said cam member beyond said article whereby said element is brought into full encircling relation with the article.

2. In a binding machine as claimed in claim 1, a welding electrode mounted on said projecting part and mobile relative to said part, and a second welding electrode mounted on said other leg..

3. A binding machine comprising a frame, a gripper assembly supported for vertical movement from said frame and comprising a pair of spaced generally vertical legs at least one of which is rockable relative to the other, means supporting an article to be bound in a position to be encompassed by said legs on downward move ment of the assembly, there being aperture means near the lower ends of said legs adapted to receive a flexible binding element therethrough, a projecting part mounted on the free extremity of one of said legs, biassing means for normally urging said projecting part toward the other leg, and a cam member on said projecting part engageable by said element and rocking said one leg outwardly during said downward movement by coaction with a surface of said article, said biassing means restoring said projecting part to its normal closed relative position with said binding element fully encircling said article.

4. A binding machine comprising a frame, a gripper assembly supported for vertical movement from said frame and comprising a pair of spaced generally vertical legs at least one of which is rockable relative to the other, means supporting an article to be bound in a position to be encompassed by said legs on downward movement of the assembly, there being aperture means near the lower ends of said legs adapted to receive a flexible binding element therethrough, a projecting part mounted on the free extremity of one of said legs, biassing means for normally urging said projecting part toward the other leg, and a cam member on said projecting part engage- 10 able by said element and rocking said one leg outwardly during said downward movement by coaction with a surface of said article, said biassing means restoring said projecting part to its normal closed relative position with said binding element fully encircling said article, and cooperating welding electrodes on said legs for welding the adjacent ends of said element in said encirling condition.

5. A binding machine comprising a frame, an assembly supported for vertical movement from said frame and comprising a pair of spaced generally vertical legs at least one of which is rockable relatively to the other, means supporting an article to be bound in a position to be encompassed by said legs on downward movement of the assembly, there being aperture means near the lower ends of said legs, a supply of a flexible bind-ing element and means for feeding said element from said supply through said apertures, means between said supply and said assembly for cutting ofi adjustably predetermined lengths of said element, and camming means on said at least one leg engageable with said element and arranged for coaction with a surface portion of said article to rock said one leg outwardly during said downward movement, power means for restoring said legs to a closed relative position on continued downward movement of said assembly with said element fully encircling the article, and means for bonding the adjacent ends of the element in said encircling position.

6. In a binding machine as claimed in claim 5, power means for imparting vertical movement to said assembly, power means for operating said feeding means, power means for operating said cutting means, power means for operating said bonding means, and electrical timing means for controlling said respective power means in accordance with a predetermined operating sequence.

7. In a binding machine as claimed in claim 5, power means for imparting vertical movement to said assembly, power means for operating said feeding means, power means for operating said cutting means, power means for operating said bonding means, at least some of said respective power means comprising pressure fluid actuators, and electrical relay means operatively connected with said respective power means and automatically operable to control the latter in accordance with a predetermined operating sequence.

. 8. In a binding machine as claimed in claim 5, spring means for biassing said legs towards each other.

9. In a binding machine as claimed in claim 5, pressure fluid actuator means contributing to restore said legs to said closed relative position.

10. In a binding machine as claimed in claim 5, presser means for pressing said binding element against the upper surface of said article.

References Cited in the file of this patent UNITED STATES PATENTS 1,417,329 Jones May 23, 1922 2,524,316 Jackson Oct. 3, 1950 2,581,776 Wallace et al. Jan. 8, 1952 FOREIGN PATENTS 203,887 Great Britain Sept. 10, 1923 744,176 Great Britain Feb. 1, 1956 

